Interactions and corrosion mitigation prospective of pyrazole derivative on mild steel in HCl environment

The effectiveness of 1H?pyrazole?3,5?dicarboxylic acid 5?benzyl ester 3?phenyl ester (PCBPE) as a preventer for deterioration of IS 513 Gr. D steel in 1 M HCl medium is evaluated via weight loss, electrochemical impedance, and polarization techniques. Kinetic and thermodynamic parameters assessed the feasibility of the adsorption process at diverse temperatures. The inhibition action on mild steel has been enhanced with increasing PCBPE concentration. It is found from the polarization studies that PCBPE behaves as mixed type inhibitor in HCl medium. The adsorption process of PCBPE on mild steel surface from acid environment is favoured Langmuir adsorption isotherm. The shielding efficiency of PCBPE has been enhanced at elevated concentrations, and it has been diminished at amplified temperatures. The Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), and Energy Dispersive Spectrum (EDS) were used to establish a surface characterization of metal specimens. A quantum chemical analysis of electron density distributions in the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) demonstrated how the inhibitor undergoes adsorption on mild steel in 1 M HCl. All experimental findings substantiate the corrosion mitigation performance of PCBPE on mild steel in acidic environments.     

High-load, soluble oligomeric carbodiimide: synthesis and application in coupling reactions

A facile preparation of a high-load, soluble oligomeric alkyl cyclohexylcarbodiimide (OACC) reagent via ROM polymerization from commercially available starting materials is described. This reagent is exploited as a coupling reagent for esterification, amidation, and dehydration of carboxylic acids (aliphatic and aromatic) with an assortment of alcohols (aliphatic primary, secondary, and benzylic), thiols, phenols, and amines (aliphatic primary, secondary, benzylic, and aromatic/anilines), respectively. Following the coupling event, precipitation with an appropriate solvent (Et(2)O, MeOH, or EtOAc), followed by filtration through a SPE provides the products in good to excellent yield and purity.     

Effect of Solvent on Third-Order Nonlinear Optical Behavior of Reactive Blue 19 Dye

Journal of Fluorescence - The present work focuses the study of effect of solvent on third-order nonlinear optical (NLO) properties of reactive blue 19 dye dissolved in various polar...     

High-load, ROMP-generated oligomeric bis-acid chlorides: design of soluble and insoluble nucleophile scavengers

[reaction: see text] An efficient strategy for scavenging a host of nucleophiles utilizing an oligomeric bis-acid chloride (OBAC), generated from the ROM polymerization of trans-bicyclo[2.2.1]hept-5-ene-2,3-dicarbonyl dichloride, is described. The reactivity and high load of the OBAC reagent is exploited in the scavenging of amines, alcohols, and thiols that are present in excess following a common benzoylation event. Following the scavenging event, these oligomers can be precipitated with EtOAc and filtered (SiO(2)), leaving benzoylated nucleophiles in excellent yield and purity.     

High-load, oligomeric phosphonyl dichloride: facile generation via ROM polymerization and application to scavenging amines

A new ROMP-derived scavenging reagent, oligomeric phosphonyl dichloride (OPC), with high-load and selectivity is reported. This reagent can be readily generated via the ROM polymerization of bicyclo[2.2.1]hept-5-en-2-ylphosphonic dichloride, which is conveniently assembled from the Diels-Alder reaction of cyclopentadiene and vinyl phosphonic dichloride. The OPC has been exploited in the rapid, efficient scavenging of primary and secondary amines that are present in excess following a common benzoylation event at room temperature (30-60 min) or under microwave conditions in shorter duration (<5 min).     

Reactive species from aromatics and oxa-di-π-methane rearrangement: a stereoselective synthesis of (±)-hirsutene from salicyl alcohol

A total synthesis of hirsutene, a triquinane sesquiterpene, from salicyl alcohol is reported. Oxidation of salicyl alcohol in the presence of cyclopentadiene gave 9-spiroepoxy-endo-tricyclo[5.2.2.0^2,6]undeca-4,10-dien-8-one which was elaborated to the 3-hydroxy-2-methyl-endo-tricyclo[5.2.2.0^2,6]undeca-10-en-8-one containing major structural and functional features of hirsutene. Photochemical sigmatropic 1,2-acyl shift in 3-hydroxy-2-methyl-endo-tricyclo[5.2.2.0^2,6]undeca-10-en-8-one followed by radical induced cleavage of peripheral cyclopropane bond, olefination and Simmon-Smith reaction furnished 11-hydroxy-1-methyl-4-spirocyclopropanetricyclo[6.3.0.0^2,6]undecane that upon treatment with hydrogen on PtO₂ and PCC oxidation gave 1,4,4-trimethyltricyclo[6.3.0.0^2,6]undecan-11-one, a known precursor. Wittig methylenation on this precursor gave hirsutene.     

Ionic immobilization, diversification, and release: application to the generation of a library of methionine aminopeptidase inhibitors

Development of an ionic immobilization, diversification, and release method for the generation of methionine aminopeptidase inhibitors is reported. This method involves the immobilization of 5-bromofuran-2-carboxylic acid and 5-bromothiophene-2-carboxylic acid onto PS-BEMP, followed by Suzuki reaction on a resin-bound intermediate and subsequent release to provide products in moderate yields and excellent purities. Compound potencies were evaluated on the Co(II), Mn(II), Ni(II), and Fe(II) forms of Escherichia coli MetAP1. The furoic-acid analogs were found to be Mn(II) selective with IC 50 values in the low micromolar range. Qualitative SAR analysis, supplemented by molecular modeling studies, provides valuable information on structural elements responsible for potency and selectivity.     

Novel entry into oxepane-diquinane and oxepane-sterpurane hybrids: synthesis and photochemistry of 3-oxatricyclo[7.2.2.0]tridecenones

A new synthesis of 3-oxatricyclo[7.2.2.0^1,7]tridecenones via intramolecular π^4s+π^2s cycloaddition in cyclohexa-2,4-dienones is described. Their photochemical reactions leading to oxepane-diquinane and oxepane-sterpurane hybrids are depicted. The crystal structure of a key intermediate is also presented.